Rake system and method

ABSTRACT

A rake system and method may include a framework, a chain, an elongated rail, a support arm, and an engagement feature. The elongated rail may be pivotably connected to the framework. The support arm may be connected to the elongated rail at a first point and may be pivotably connected to the framework at a second point. The engagement feature may be connected to the support arm and may be configured to engage the chain. The rake system may be configured to discard debris.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/930,216, filed on Sep. 7, 2022, which is a continuation of U.S.patent application Ser. No. 15/461,602, filed on Mar. 17, 2017, which isa continuation of U.S. patent application Ser. No. 14/326,548, filedJul. 9, 2014, which claims the benefit of U.S. Provisional patentapplication Ser. No. 61/843,948, filed on Jul. 9, 2013. The disclosuresof all of the foregoing are hereby incorporated by reference in theirentireties as though fully set forth herein.

TECHNICAL FIELD

This application deals with an apparatus for removing debris from watercontaining debris. Such apparatus may be found generally in wastewaterclean-up situations for example, in municipal sewage systems and thelike.

OVERVIEW

What is disclosed and claimed herein are apparatuses, methods and novelcomponent parts for removing debris from water. Novel component partsinclude among other, dual wiper blades, flexing apparatus for moving thechain of the chain drive of the apparatus whenever large materials arecarried on the skimmers, pivotal drive head that works in conjunctionwith the flexing apparatus if both are installed on the apparatus, and apivoting closure cap, rotating effector plates, along with modules ofeach of these novel components, in addition to a novel secondary skimmerdevice useful with primary skimming devices.

In a first embodiment, there is a component part which is a flexingapparatus for a flex rake.

A second embodiment of this disclosure is a rake screen apparatus havinga flexing apparatus of mounted to a framework of the rake screenapparatus.

Thus, what is disclosed is a flexing apparatus for a flex rake. Theflexing apparatus comprises a pair of elongated rails, each rail havinga top end, a bottom end, a first attachment point and a secondattachment point. The first attachment point is located near the top endof each of the elongated rails, and each second attachment point islocated near the bottom end of each said elongated rail.

A first support arm is attached at each attachment point, and each ofthe first support arms has a distal end, wherein each distal end isfixedly attached to the sidewall of an enclosure for the flexingapparatus.

Attached near each first support arm distal end is a second support armfor enhancing the movement of a chain and the bottom end and the top endof each elongated rail has a roller for enhancing the movement of achain adjacent each elongated rail.

A third embodiment of this disclosure is a component part which is adual wiper blade assembly for a rake system. The dual wiper bladeassembly comprises a pair of support members each having a near end anda distal end, wherein each near end has a pivotal attachment capabilityfor attaching to a framework of a rake system. The distal end of thesupport member has attached to it, holders, wherein each holder has abottom edge.

Each bottom edge has a first notch in it and a spaced-apart second notchin it. There is a common first wiper blade attached in the first notchesand a common second wiper blade surmounting the first wiper blade andattached in the second notches.

A fourth embodiment of this disclosure is a rake screen apparatus havinga dual wiper blade assembly as set forth just Supra, mounted to aframework of the rake screen apparatus.

A fifth embodiment of this disclosure is a stand-alone modular unitcomprising a bar screen, the modular unit configured to replace a barscreen in an existing rake screen apparatus.

In addition, there is an embodiment which is a stand-alone modular unitcomprising a perforated plate assembly, wherein the modular unit isconfigured to replace a perforated plate assembly or bar screen in anexisting rake screen apparatus.

An additional embodiment of this disclosure is a component which is apivoting drive head apparatus for a rake screen. The pivoting drive headcomprises a pair of spaced-apart, parallel support members, eachparallel spaced-apart member having a near end, a distal end and amiddle portion.

Each near end is pivotally attachable to a framework of a rake screenand each parallel support member is pivotally attached to a drivesprocket, wherein each drive sprocket is mounted on the ends of a commondrive shaft therebetween. Each drive sprocket is attached to eachrespective parallel support member near the middle portion of theparallel support member. Each distal end of the parallel support memberare configured as a stop foot. Each parallel support member, eachsprocket and the common drive shaft are pivotable away from the rakescreen framework.

Still further, there is an embodiment which is a rake screen apparatushaving a pivoting drive head apparatus mounted to a framework of saidrake screen apparatus. In addition, this arrangement can also have aflexing apparatus incorporated into the rake screen.

The rake screen apparatus can have a fixed drive head and a flexingapparatus in combination.

Yet, there is another embodiment of this disclosure which is a componentwhich is a pivoting closure cap for a rake screen apparatus having sideframework. The pivoting closure cap comprises a top panel, two mirrorimage side panels having edges and, top front corners, which is attachedat the edges to the top panel. There is a back panel having edges andattached at the edges to the top panel and the side panels.

Each side panel is configured to accommodate any components extendingbeyond the side panels such that the components will not interfere withclosure of the pivoting closure cap. There is a flexing enclosure lid,pivotably mounted at the top front corners of the side panels.

A sixth embodiment of this disclosure is a combination of a rake screenapparatus and a pivoting closing cap as set forth just Supra, in whichthe pivoting closing cap is mounted to the framework of the rake screenapparatus.

Further, there is an embodiment which is a rake screen apparatuscontaining in addition, in combination, a flexing apparatus, a dualwiper blade assembly, a pivoting drive head apparatus, a pivotingclosure cap, a revolving effector plate apparatus, and a secondaryskimming device that follows after the primary skimming device.

A seventh embodiment of this disclosure is a rake screen apparatus inwhich screens, drive mechanisms and enclosures are all modular, whereineach of the screens, drive mechanisms and enclosures can be removed orreplaced without disassembling the entire rake screen apparatus.

An eighth embodiment of this disclosure are the modular components, forexample, a screen module, a drive module containing a drive and askimmer system, an enclosure module that has the ability to be modifiedto create clearance for various size debris moving through a rakescreen, and a modular component for a rake screen that is a flexingapparatus, a rotational effector plate, along with a secondary skimmingdevice.

A ninth embodiment of this disclosure is a rotational, moveable,effector module for use with a trash rake. The rotational, moveable,effector module comprises a frame, wherein the frame has a top end, andbottom end, and two sides.

There is a first common axle extending between the two sides near thetop end and a second common axle extending between the two sides andlocated beneath the first common axle. The first common axle and thesecond common axle are driveably connected by a common drive assembly.The second common axle has a sprocket located at each end, each sprockethaving a drive chain located on it, the chains having a lower end. Thechains are not mounted on a sprocket at the lower end.

There is a plurality of cross members equally spaced between the chainsand each cross member has mounted on it, skimmers. Each skimmerinterfaces with a backside of a perforated plate filtration screen of atrash rack, and each shimmer has a leading edge.

Optionally, the leading edge of each primary skimmer in a flex rake hasa thin, flexible sheet attached to it in a manner sufficient to apply alow, consistent force along a leading edge of the thin, flexible sheet,against a surface of a perforated screen.

The present disclosure provides methods of operating a rake system. Forexample and without limitation, a method may include providing a rakesystem having a framework, a chain including a plurality of skimmers, anelongated rail, a first support arm connected to the elongated rail at afirst point and to the framework at a second point, a second support armconnected to the elongated rail at a third point and to the framework ata fourth point, the second support arm disposed lower that the firstsupport arm, a first guide device connected to the first support arm, asecond guide device connected to the second support arm, the first guidedevice and the second guide device configured to engage the chain, andthe first guide device and the second guide device spaced apart from andnot in direct contact with the elongated rail, and/or a screen, rotatingthe chain, receiving debris between the chain and the screen, and/ormoving the debris along the screen, via a skimmer of the plurality ofskimmers, to discard the debris.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a full side view of a prior art flex rake for cleaning debrisfrom water.

FIG. 2A is a full side view of a flexing apparatus of this disclosuremounted within a flex rake, inside the chain, in a normal operatingposition, wherein the drive head is stationary.

FIG. 2B is a full side view of a flexing apparatus of FIG. 2A whereinthe flexing apparatus is in a flex position wherein the drive head isstationary.

FIG. 2C is an enlarged full side view of a flexing apparatus of FIG. 2Ashowing detail of the mounting.

FIG. 3A is an isometric view of the dual wiper blade mounted on the flexrake apparatus.

FIG. 3B is a full side view of the dual wiper blade apparatus mounted onthe flex rake apparatus.

FIG. 3C is a full back view of the dual wiper blade apparatus mounted onthe flex rake apparatus.

FIGS. 3D to 3H illustrate the progressive movement of the dual wiperblades across the skimmer moving from left to right.

FIG. 4A is a full side view of the mounting apparatus for the pivotaldrive head showing the normal operating position of the drive head.

FIG. 4B is a full side view of the mounting apparatus for the pivotaldrive head showing the pivoted position when a large object isencountered on the skimmer blade.

FIG. 4C is a full front view of the mounting apparatus for the pivotaldrive head.

FIG. 4D is an isometric view of the mounting apparatus for the pivotaldrive head.

FIG. 4E is a full side view of the mounting apparatus for the pivotaldrive head.

FIG. 4F is an enlarged view in perspective of a stop foot of thisdisclosure.

FIG. 4G is a view in perspective of a pivot head of this disclosureillustrating the placement of the stop foot.

FIG. 5A shows a view in perspective from the front of a screen module.

FIG. 5B shows a full side view of the screen module.

FIG. 5C shows a full view in perspective from the back of a drive moduleand flexing component.

FIG. 5D is a full side view of the drive module and flexing component ofFIG. 5C.

FIG. 5E is a full view in perspective of the enclosure module of thisdisclosure.

FIG. 5F is a full side view of the enclosure module of FIG. 5E.

FIG. 5G is a full view in perspective from the front of the flex rakeshowing a bar screen module.

FIG. 5H is a full view in perspective from the front of the flex rakeshowing an effector module.

FIG. 5I is a full back view of an effector module showing the watersystem and other components.

FIG. 6A is a full side view of the normal operating position of theenclosure cap.

FIG. 6B is a full side view of the pivot out position of the enclosurecap of FIG. 6A.

FIG. 6C is a full side view of the pivoting position for inspection ofthe interior of the enclosure cap and the pivot head.

FIG. 7 is a full view in perspective from the front, of a primaryskimmer bar showing the skimmers.

FIG. 8 is an enlarged primary skimmer showing the secondary skimmers inplace.

FIG. 9 is a full view in perspective of the plate with attachedsecondary skimmer that is used to mount the secondary skimmer on theprimary skimmer.

DETAILED DESCRIPTION OF THE DISCLOSURE

Turning now to the detailed description of the disclosure, there isshown in FIG. 1 , a prior art flex rake apparatus 1 having a thin plateapparatus for removing debris from water. The purpose of inclusion ofthis in the disclosure is to show the conventional parts of such anapparatus.

There is shown in FIG. 2A, which is a schematic of the internalapparatus of a flex rake, a portion of the first novel component of thisdisclosure. There is shown two, parallel elongated rails 33 (only oneshown). There is a first support arm 2 used in conjunction with thepivotal head 8 (FIG. 4A) of the flex rake to move the drive chain 3 outof line with regard to any large object 4 (e.g., debris) (FIG. 2B) thatis brought from the water to the surface for disposal and at the sametime, maintaining the skimmers 5 in position near the screen 6. Thelarge object 4 has a tendency to obstruct the apparatus and make itineffective for the work that it is supposed to do. FIG. 2A shows thenormal position of the chain 3, and FIG. 2B shows the chain 3 in aflexed position. FIG. 2C is an enlarged figure to show the mounting 10of an upper and a lower first support arm 2 and the elongated rail 33.The distal end 42 of the upper first support arm 2 may be attached to aside wall 40 of a housing for the flex rake apparatus at attachmentpoint 41 and the distal end of the lower first support arm 2 may beattached to the side wall 40 at attachment point 45. Also shown is aguide device 34 (e.g., a roller, a guide, a contour member, and/or anengagement feature) mounted at or about the top 43 and at or about thebottom 44 of the elongated rail 33. Each of the support arms 2 may havemounted on it at a distal end a guide device 35 (e.g., a roller, aguide, a contour member, and/or an engagement feature) configured toassist the movement of and/or engage the chain 7.

The pivoting drive head is comprised of a hinging drive head 8, drivesprocket 9, parallel support members 53.

When the flex rake is installed at 30 degrees from vertical, twomechanisms accomplish this. First, the weight of the chain 3 andskimmers 5 leaning at 30 degrees along the surface of the screen 6 alongwith the flexing capability of the flex links 7 (FIG. 2A) of the chain 3creates skimmer contact with the screen 6 along with the ability to flexaway for larger debris. The second feature that creates thisfunctionality at 30 degrees is the hanging drive head (pivotal drivehead) 8, FIGS. 4A to 4E. The pivotal drive head 8 and the drive sprocket9 swing out of the way (See FIG. 4B) when large debris moves up to thetop of the screen 6. In a vertical or near vertical application, thisfunctionality is lost. At vertical or near vertical, the skimmers 5 donot push up against the screen 6, but instead they hang freely from thedrive sprocket 9. This creates a problem because without the pressure ofthe skimmers 5 to the screen 6, debris can get between the skimmers 5and the screen 6 and fall back down into the water channel.

In order to create this functionality at all angles including vertical,the inventors herein have created a novel disclosure that gives the samefunctionality at all angles. The pivotal head 8, the drive sprocket 9,and the support arm 2 are attached to the structure of the machine insuch a way that they pivot to engage with the chain 3 in order to applypressure to the skimmers 5 into the screen 6 while still allowing thechain links 7 to flex away from the screen 6 by pivoting out of the way.

This apparatus can be used in flex rakes having fixed drive heads, aswell as pivotable drive heads. In prior apparatuses, the drive headswere not fixed, that is, they had to be pivotable in order to pass theobstructions provided by large objects. Now, there is a means of usingfixed heads in such apparatuses. This component allows the flex rake tobe used essentially vertically, or it can allow the flex rake to be usedon an angle relative to vertical.

The pivotal drive heads 8 of this disclosure are also novel, in that,the same functionality can be had in all configurations of the flexrake. The pivoting drive head 8 can be used without the flexingapparatus in flex rakes installed at 15 degrees from vertical or higher.

A shown in FIG. 4A, the pivotal drive 8 head comprises a pair ofspace-apart, parallel support members 54, wherein each such member 54has a near end 55, a distal end 56 and a middle portion 57 (see FIG.4D). Each of the near ends 55 is pivotally attached at 58 to a framework59 of the rake screen. Each member 54 is pivotally attached at 60 to adrive sprocket 9 that is mounted on the ends of a common drive shaft 62.Each of the drive sprockets 9 is attached to each respective parallelsupport member 63 near the middle portion 57 of the parallel supportmember 54. The distal end of the member 54 has attached thereto a stopfoot 65 for the apparatus (see FIGS. 4F and 4G). The stop foot 65 hasmounted on it a foot 68 having two faces 66 and 67. These two faces 66and 67 are stop points for the rotation of the pivot head andessentially stop the pivot head 8 from a full rotation. The pivot head 8can only rotate to the extent that it engages with one of the two faces66 and 67. Each of the support members 54, sprocket 9 and the commondrive shaft 62 are pivotable away from the rake screen framework to thatextent.

The flexible chain links 7 function by holding pressure to the screen 6using the weight of the chain links 7 and skimmers 5, then flexing outof the way for large debris 4 when the large debris 4 gets to the top ofthe screen. Instead of the drive head 8 swinging out of the way with theanchor points 30 above the drive head 8, it pivots out of the way withthe anchor points 30 below the drive head 8. The pivoting drive head 8can also be used in applications installed at 0 to 15 degrees inconjunction with the flexing apparatus.

Turning now to the duel wiping blades 11 of this disclosure, there areseveral known debris blades currently in use, however, they are singlewiper blade apparatuses. Wiper blades of this disclosure are shown inFIGS. 3A to 3H. One of the largest problems in the industry withcleaning skimmers 5 is the fact that they may not completely clean eachskimmer or wipe the wrapped “rags” off when they swipe the skimmers 5.The novel duel blades 11 of this disclosure wipe each skimmer 5 twiceeach time that the skimmer 5 passes this cleaning mechanism. Thisensures that debris is cleaned off the skimmer 5 by fully wiping theskimmer 5 at least two times. Shown in FIGS. 3A, 3B, and 3C, is theposition of the dual wiper blades 11 within the flex rake apparatus.

Shown in FIG. 3D is the first wiping blade 47 that is fixed in a firstnotch 37 in support 38 and second wiping blade 48 is fixed in a secondnotch 37 in support 38. Moving from FIG. 3D to FIG. 3H, the operation ofthe dual wiper blades 11 is sown.

The enclosure cap 12 of this disclosure is designed to cover the top ofthe flex rake and its top most components (See FIG. 6A). The enclosurecap 12 of this disclosure is also designed to allow the enclosure cap 12to pivot out of the way (See FIG. 6B) when a large object 4 arrives atthe top of the mechanism. In addition, the enclosure cap 12 of thisdisclosure will open widely to allow for the inspection and removal ofdebris that may become jammed in the apparatus (See FIG. 6C). theclosure cap 12 is comprised of a top panel 49, a bottom panel 50, twoside panels 51 (only one side shown) and a front panel 52. As shown inFIG. 6C, the cap 12 opens, or pivots away from the top of the flex rakeapparatus to allow access into the interior of the flex rake upper area.

A very novel feature of this disclosure is the modularity that is builtinto the flex rake. The newest versions of the flex rake that arecovered by this disclosure are designed in modules such that eachsection of the machine houses different components. The flex rake has ascreen module 13, FIGS. 5A and 5B, a drive module 14, FIGS. 5C and 5D,an enclosure module 15, FIGS. 5E and 5F, and an effector module 16.FIGS. 5H, and a portion of an effector module 51, can also be added asdifferent modules to the flex rake. Each section can be used orexchanged to accommodate various functionalities as needed. FIG. 5Gshows the drive module 14 and screen module 13 in combination. FIG. 5Hshows a combination of a drive module 14, a screen module 13 and aneffector module 16 in combination.

For example, in order to modify a ¼ inch teardrop bar screen 17 as shownin FIG. 5G, to a ¾ inch teardrop bar screen the only module affectedwould be the screen module 13. The drive module 14 and enclosure module15 would remain the same. This modularity allows for greater flexibilityin design and functionality for the new flex rake equipment. The newequipment could have a ¼ inch teardrop bar screen that has beenunchanged except for the screen module that has been changed to a ¾ inchteardrop bar screen. If a customer had this need the flex rake can beadapted to that need without replacing the whole piece of equipment.

The disclosure herein has another novel feature, and that is thecapability of not only replacing individual modules, but also to addmodules as necessary to increase or change the functionality of the flexrake.

With reference to FIGS. 5G and 5H, there is shown a machine with a ¼inch teardrop screen in the screen section that is replaced by a 2 mmperforated screen 6 for that section (FIG. 5G). A flexing apparatus isadded to the machine to work in conjunction with the 2 mm perforatedscreen (FIG. 5H). The existing drive section 14 and enclosure sections15 remain the same except for the addition of a drive shaft and gearboxthat is used to power the flexing apparatus module.

Various screen sizes and configurations can be exchanged in the screensection without affecting the other modules. The enclosure section canbe modified or exchanged to accommodate larger debris as requiredwithout affecting the other sections of the machine. The drive sectioncan be modified to accommodate higher speeds or lifting capacity withoutaffecting the other modules, and other modules can be added to themachine for other capabilities such as the flexing apparatus modules asshown in the FIG. 5H.

It is also contemplated within the scope of this disclosure tocompletely enclose the flex rake of this disclosure with all of itscomponent parts. Such an enclosure is illustrated in FIGS. 5E and 5F.

The novel effector module 16 of this disclosure is illustrated in FIG.5I and consists of a frame 32 consisting of two sides 18 and 18′ and acommon axle 19 between them which is located near the top 20 of theeffector module 16.

There is also shown a second common axle 21 which is located between thesides 18 and 18′. Shown at one end of the axle is a drive mechanism thatin this particular case, is commonly driven by a motor 22 shown in FIG.5H and a drive mechanism 23 consisting of normal accompanying gears andthe like. The second common axle 21 is driven by the drive mechanism 23and drives sprockets (not shown) that have flex linked chains 24 on eachend of the second common axle 21 that has attached to it a series ofeffector plates 25, which effector plates 25 are configured to alignwith the perforated screen 6 (best shown in FIG. 5H). The effectorplates 25 are perforated 26 such that water can flow from them.

The effector plates 25 are equipped to receive water from a deliverysystem illustrated generally as 27, and are synchronized to allow theflow of water when they are aligned with the perforated plate 6. Onlyone series of effector plates is shown for clarity, it being understoodthat there are multiple cross members 25 and multiple series of effectorplates 25 in the apparatus.

The removal of debris from a statically positioned perforated screen forthe purpose of water filtration requires a very distinct series ofdynamics to effectively remove the debris without applying destructiveforces to the perforated screen element.

The application of a statically positioned screen inherently requiresthe debris to be removed from the screen area that is at the effect ofthe hydrostatic and flow forces of the incoming dirty water. The firstdynamic necessity is to reduce or remove the hydrostatic pressureholding the debris against the screen over an area large enough todislodge the debris relative to the size of the debris.

In the case of the application of a statically positioned perforatedscreen in municipal waste water, this debris can range from essentially0.0001 m2 to 0.1 m2. Failure to reduce or remove the hydrostatic forceholding the debris to the screen element will result in the failure toeffectively remove the debris, unless scraping forces that exceed thehydrostatic forces are applied to the moving of the debris along thescreen surface, which in prior art devices, damage occurs to the screenelement.

To reduce or remove this hydrostatic force in the case of the perforatedplate screen, a device called an Effector™ (Duperon Innovations,Saginaw, Michigan USA) is positioned very near to or intimate to thedownstream side of the perforated screen. This device reduces or removesthe hydrostatic on the debris by transferring these forces to thesurface of the device near or intimate to the screen. In addition tothis transfer of force, a diverted flow pattern is created about thedevice.

This diverted flow pattern has a distinct effect on any debris that isdislodged. This effect can and will move debris along the surface of thescreen by utilizing the higher velocity flows diverting around thesurface of the Effector device that is near or intimate to the screen.In addition and related to this diverted flow pattern, a low forcepocket is formed on the upstream side of the screen in front of theEffector, relative to the size of the Effector and the velocity of theincoming water stream.

This low force pocket forms a space for the debris to gather after ithas been removed from the screen. In addition to the function of theEffector, there is a sprayer integrated into the Effector, spraying fromthe downstream through the screen to the upstream side of the screen.The purpose of the sprayer is to positively dislodge the debris from thescreen that has stapled (reached through) the perforations of thescreen. The sprayer is positioned relative to the low force pocket.

To collect the dislodged debris and transfer it to discharge point, askimmer device 5 positioned on the upstream side of the screen 17 movesrelative to the position of the Effector plate 25. The position of theskimmer device, relative to the Effector, is critical to the distinctformation of the low force pocket and the direction of the diverted flowpattern in front of the Effector plate 25.

Each of these dynamics are interdependent. The reduction or exclusion ofany of these dynamics greatly reduces or negates the ability to removethe debris from the statically positioned perforated screen in thedesign of the perforated plate. For example, by eliminating the lowforce pocket in front of the Effector, the sprayer, in and of itself, isunable to neatly remove the range of debris from the screen so theskimmer device can collect the debris for transport. This is due to theeffective spray force required for debris with a large area whichdiffers greatly from that required for small debris, in an uncontrolledenvironment. The combined effects of the low force pocket and thediverted flow patterns, equilibrate the spray forces required to neatlydislodge the debris from the screen and allows the skimmer device 5 tocollect the debris.

In addition to the primary debris removal device used in the clearing ofdebris from a perforated plate filtration screen, such as a skimmer,scraper or sprayer, a novel secondary skimming device 28 follows afterthe primary, attached to, or near to the primary device (trash screen),or in a position preceding the introduction of more debris to theperforated screen. Preferred mounting is to have the secondary skimmermounted on the bottom of the primary skimmer, and extending forward pastthe leading edge of the primary skimmer, (See FIGS. 7 and 8 ), using amounting plate 29 as shown in FIG. 9 .

The purpose of this device is to clear fibrous material from the screenthat has reached through the perforated screen and is unaffected bytypical primary removal devices. This failure of fibrous debrisremaining on the screen is called “stapling”.

The device is a thin and flexible sheet that is formed, or fixed to itsattachment point, in a manner to allow consistent force along its edge,to the surface of the perforated screen. The material hardness of thesheet is designed to be sacrificial to the perforated screen and thethickness of the sheet is designed to maintain a consistent effectivesharpness along its edge regardless of wear along the edge of the sheet.

The ability of the device to remove singular fiber or masses containingmultiple fibers lies in the combination of the low consistent force andconsistent effective sharpness. As the device moves along the inlet sidesurface of a perforated screen, the sharp edge gathers the fibrousmaterial and moves it along the surface of the perforated screen to apoint where it can be discharged.

This device is affixed to the bottom surface of the primary skimmerssuch that it touches the perforated screen, and hence, the fibrousmaterial positioned in the perforations of the perforated screen. (SeeFIG. 4A).

What is claimed is:
 1. A rake system, comprising: a framework; a chain;an elongated rail pivotably connected to the framework; a support armconnected to the elongated rail at a first point and pivotably connectedto the framework at a second point; and an engagement feature connectedto the support arm and configured to engage the chain; wherein the rakesystem is configured to discard debris.
 2. The rake system of claim 1,wherein: the elongated rail spans a first distance; the chain spans asecond distance; the first distance is less than the second distance;and the chain includes a plurality of chain links.
 3. The rake system ofclaim 1, wherein: the rake system includes a plurality of skimmers thatare connected to the chain; the skimmers are spaced apart along thechain; and the skimmers extend outwardly from the chain.
 4. The rakesystem of claim 3, wherein the skimmers are configured to contact ascreen of the rake system.
 5. The rake system of claim 4, wherein therake system is configured to receive the debris between the chain andthe screen.
 6. The rake system of claim 4, wherein the rake system isconfigured to move the chain such that a skimmer of the plurality ofskimmers moves the debris along the screen.
 7. The rake system of claim1, including a sprocket that is operable to drive the chain.
 8. The rakesystem of claim 7, wherein the sprocket is disposed proximate an upperportion of the framework; and a lower portion of the framework does notinclude a sprocket.
 9. The rake system of claim 1, including a motorconfigured to advance the chain; and no drive mechanism is located at abottom of the rake system.
 10. The rake system of claim 1, including: anadditional support arm pivotably connected to the framework; and anadditional engagement feature connected to the additional support arm;wherein the engagement feature and the additional engagement feature areconfigured to manipulate the chain.
 11. The rake system of claim 1,wherein the framework extends in a vertical direction.
 12. The rakesystem of claim 1, including a screen; wherein the rake system isconfigured to move the debris in a direction parallel to the screen. 13.The rake system of claim 1, including a screen; wherein the rake systemis configured to move the debris in an upwards direction relative to theframework.
 14. The rake system of claim 1, wherein the enhancementfeature is operable to apply a force on a skimmer to enhance debrisremoval.
 15. The rake system of claim 14, including a third support armconnected to the additional elongated rail.
 16. The rake system of claim15, including a fourth support arm connected to the additional elongatedrail.
 17. A method of operating the rake system of claim 1, comprising:rotating the chain; receiving the debris between the chain and a screen;moving the chain relative to the framework; and moving the debris alongthe screen, via a skimmer, to discard the debris.
 18. The method ofclaim 17, wherein moving the debris along the screen includes moving thedebris in a direction parallel to the framework.
 19. The method of claim17, including applying pressure to at least one skimmer into the screento maintain movement of the debris.
 20. A method of operating a rakesystem comprising: providing: a framework, locating the frameworkrelative to ground in a non-vertical orientation, a chain, an elongatedrail pivotably connected to the framework; a support arm connected tothe elongated rail at a first point and pivotably connected to theframework at a second point; an engagement feature connected to thesupport arm and configured to engage the chain; and configuring the rakesystem to discard debris.